I use Enterprise Architect by Sparx Systems to create my UML. Unfortunately, the code generated looks like this

public class Customer{

}

There is no option to change this behavior in EA. To get this to happen in EA you need to modify the code generation template for C#. Go to Settings, Code Generation Templates and select C#. Using the code below update the EA templates for the sections in the headers with ======== underneath. For properties the item you need to select Operation Body and then in the list box below the main list box select Property. Remember to click save for each section that you modify. If you don't like the changes you can click the Get Defaukt Template button for each section.